Apparatus for printing, sheets, films or lengths of material, notably textile material, by means of screen printing



Aug. 14, 1956 R. R. LAUPMAN 2,758,540

APPARATUS FOR PRNTING, SHEETS. FILMS OR LENGTHS OF MATERIAL, NOTABLYTEXTILE MATERIAL, BY MEANS OF' SCREEN PRINTING Filed May 1, 1952 ssheetsfshee. 1

2,758,540 LIGTHS llg- 14, 19::6 R. R. LAUPMAN APPARATUS FOR PRINTING,SHEETS. FILMS OR F MATERIAL, NOTABLY TEXTILE MATERIAL MEANS OF' SCREENPRINTING 3 Sheets-Sheet 2 Filed May l. 1952 INVENTOR Rer? Lau/oma);

ug- 14, 1956 R. R. LAUPMAN 2,758,540

APPARATUS FOR PRINTING, SHEETS, FILMS OR LENGTHS OF' MATERIAL, NOTABLYTEXTILE MATERIAL, BY MEANS OF` SCREEN PRINTING Filed May l, 1952 3Sheets-Sheet 3 FEA-925 INVENTOR. ROBERT R. LAUPMAN BY WM,MM PMAATTORNEYS United States Patent APPARATUS FOR PRINTING, SHEETS, R i

L'ENGTHS 0F lVIAERINL., NOTABIlY 'TEXTILE MATERIL, BY A'0F TSCREENRINTJNG Robert Ronald Laupman, Wychen, Netherlands Application May -1,1952, fSexial No."2f8i5,`512 Claims priority, 'application NetherlandsMay 2v, 1-951 3 Claims. (Cl. lill-'126) YThese steps areintermitftent.-In many "ways it lhas been tried -to meehanize these steps:electrically, with 'the vhelp of contact rollers and relays,vmechanically with the'help `or" various cams, ratchet mechanisms, etc.However, towing 'to their being highly complicated lthe machines whichmechanize the steps in question AAgive -rise 'to the `danger that oneo'f their parts will stall, soth'atmisprints will -result which canvdestroy an lentire ilength of cloth.

Now it is an object of the present invention to carry .out the saidsteps by means o'f a 'very simple apparatus,

`said steps 'being split -up into -two groups:

l. rPhe steps ysynchronous with fthe passing on of the cloth;

2. The movement of the squeegee.

The apparatus according to'the :invention is based on a very simplepinciple, which, however, by its very simplicity, opens up veryvattractive perspectives from the vpoints of view of construction andfoperation.

The new vapparatus is ycharacterized `Ain 'thatzin the lifted couplingv.periodically displaces E'the conveyor 5-belt for the Imaterial it'o beprinted. f

rif llarge lengths are to =be printed, so l'that Athe size ofIth'efscreen 'orfscreens -is insu'i'cienn it fis possible, if more thanone fsqueegee is lused, Lto make the squeegees adjustable in verticaldirection relatively to the squeegee carrier -by means of 'a facqu'ardmechanism.

This iis also 'very-suitable for obtaining a greater `vari ation in lthepattern.

The invention is further elucidated hereinafter with reference to .theaccompanying drawing.

In this drawing:

Fig. l is a diagrammatic Iside view'of 'the screen printing machine;

Fig. la is a side viewfof the ends Y'ofthe carrier belt .for 'thematerial to be printed;

Fig. 2 on va larger scale `shows 'a-cross section taken -on the 'lineIII-II gin Fig. 7l;

'Fi'g. 3 .isra 'fragmentary'viewzof the cam disc for lifting andlowering the lscreen support and the 'squeegee-carrier;

lFi'g. Zldiagrammatically `shows the movement of a squee- 'gee `rbetweentwo subsequent worlcing end positions;

Pig. '5 is ,a planview of a inumber -of screen frames, each 'providedwith va printing screen;

yFig. .6 on 'alarger scale s'howsf'a-'cros's section taken on vthe lineXII-@VI in fFig. il. Y

`JR'eferring to fthe drawings, the screen printing machine comprises amain frame il,which carries at v'its ends rollers 3 land2f7for-supportingan endless belt y2'6which is driven intermittently fandia'dju'stably tolmovethe 'fabric '28 Yto .be

printed successively 'to the printing positions.

position the squeegee performs an/even number of `inoper ative strokes,starting ljustbe'fore the squeezed oli print ing paste 4and ending justbehind said v-printing paste, to subsequently perform a numberofoperative stro'keswhich number is smaller than the numberof'inopera'tivestrokes.

A suitable embodiment comprises two rotating driving shafts or spindles,"one of which `periodically idisplaces the material to be printed, whilethe other shaft or spindle imparts a reciprocatory movement to asqueegee-carrier, adapted to be V'lifted by meansof azcam or cam disc,which is rotated vby said first-named spindle, the screen being liftedby the same or by anothercamf'o'r cam discrotated by said spindle, theratio between the numbers v'of revolu- .tions of said spindles or shaftsAbeing 2: {llaa-431), -inlwhi'ch formula x and y 'represent integerswhich 'at"lea'stequa'l vvl.

If only one cam disc is used, :it is 'to be :recommended that vthe partcooperating with this cam disc and lifting the squeegee carrier likewisecooperates with some play with the screen part to be lifted.

In order -to enable the material to be printed lto vbe passed onperiodically it is of advantage if the `lrs't shaft rotates an arm thelength of which l'is preferably adjust'- able, which arm drives aone-way coupling in opposition 'to a spring -by means of a chain orato'othed rack, which The fabric 28 is fed from asupp'lyreel 29 and issecured to the be'lt lby means o'f fan'a'dhesive. n After-the `fabric28,ha's been -print'edfit leaves the feXit end of the .machine and isfstrip'ped 'from lthe 'ebelt '26 by a stripping knife 30. Y

The :main frame -1 gis further provided with a -motor f2 for driving theshafts 4 and 1l), which 'shafts are rotatab'ly t-supported by the mainIframe 1 vand which are each provided with a gear. The Igears a'r'eIinterconnected with `ea'c'h 'other 'and with the lmotor "by .a drivingchain l3.

.Am Iarm 5 ixed to one fend 'df 'the shaft l lhas lan adjustable sleeve6 thereon Ito which l"a Icable 7 is secured, whichfcableiisfpassedoverfapulley-of a one-way coupling ion'the :roller 8. The lofther'end of 'cable 7 lis secured -to a drawspring 9 which is llixed ltorthemain frame '1.

During the rotation of theshaft 2i, `driven by the motor f2, the rollerS together 'with fthe 'endless belt 25 and ythe :fabric 28 isintermittently dxven to advance vthe vvfabric ZS vfrom fone position ttofthe next. The distance the belt moves on each stroke may be adjustedfby adjusting the position of-sleeve 6.

iA V,framework composed of longitudinal -rods 16 and :17 pivoted'to eachother at their adjacent ends at 1S and cross bars 22'and S24,Vis-sosusp'ended fromthe ylongitudinal walls of .the 'main frame 1 lthatthe Itwo `halves of said framework are adapted :to .oscillate labout theshafts .20 :and '21 respectively.

The framework lcarries rollers 25 :at its two longitudinal sides, onwhich rollers a squeegee -carrier A.14 bears. A number :of 'squeegees 34are secured :to vthe ycarrier by means -of cross bars 33 and clamps 32.The squeegee carrier is adapted to travel over the rollers 25. The

squeegee carrier 14 .isprovided with an .arm .31 to which the one end ofva connecting rod 13 is coupled. The other end is coupled by anadjustable sleeve l2 to an arm 11 secured to the Vshaft 10.

'During the rotation of the shaft 10 which isdriven by the motor 2, `the'squeegee carrier '14 is lreciprocated over the rollers v25 by the`connecting rod v13.

l "Within the space defined by thesqueegee carrier 14 a support for anumber of screens is located. This screen support consists of aframestructure composed of longitudinal and transverse rodsc41 and 4t)and of auxiliary rods 43. The hooks 39 of supporting rods 38 are securedthereto by means of bolts 42. Said supporting rods 38 serve for securingthereto the screens, which screens consist of a metal frame 37surrounded by a wooden framework 36 against the lower side of which apatterned piece of gauze 35 is secured.

The longitudinal rods 41 of the screen support are provided withvertically adjustable pins 15 and 23 which end at some distance abovethe cross bars 22 and 24 of the framework 16 and 17. The transverse rod22 in the framework carries a roller 19, which bearson the circumferenceof a cam disc 46 secured to the shaft 4.

During the rotation of the shaft 4 and the cam disc 46, the roller 19resting on the cam disc will lift the outer ends of the rods 16 and 17upwardly and downwardly so that the squeegee carrier 14, supported onthe rollers 25, together with the squeegees 34 is likewise movedupwardly and downwardly. During the upward movement of the outer endstofthe rods 16 and 17 the ends thereof will contact the lower ends of thepins 23 and 15 and the screen support will be moved upwardly. Duringthe` downward movement of the outer ends of the rods 16 and 17 thescreen support will follow this` downward movement until the auxiliaryrods 43 of the screen support come to a standstill by their runningagainst the main frame 1. The lower ends of the pins4 23 and 15 will nolonger contact the levers 16 and 17 during `the subsequent lowering ofthe squeegee carrier 14.

During the upward and downward movement of the squeegee carrier and thescreen support and during the intervals between said upward and saiddownward movement the squeegee carrier 14 performs an uninterruptedreciprocatory movement over the rollers 25.

For timing said upward and downward and reciprocatory movements thechain gears secured to the shafts 4 and 1t) are so constructed in theembodiment shown that the shaft 4 will perform two revolutions in thetime during which the shaft 10 performs three revolutions, and the canidisc 46 secured to the shaft 4 has a circumferential shape as shown inFig. 3.

As long as the roller 19 bears on the portion of the largest radius ofthe cam disc 46, the screen support and the squeegee carrier 14 will belifted in the highest position so that they are free from the carrierbelt 26 carrying the fabric 2S. The belt 26 with the fabric 28 will beadvanced by the rotating arm 5 and the cable 7 to a next printingposition. All of this happens during a rotation of the cam disc 46 overthe angle Ta.

After (in case of the cam disc 46 having the direction of rotation shownin Fig. 3) the radius I has passed the roller 19, the screen support andthe squeegee carrier will start moving downwardly.

when the point of intersection of the circumference of the cam disc andthe circle g passes the roller 19 the screen support has reached itslowest position and the screens (47, 48, 49, Fig. 5) will lie on thefabric 28.

When the point of intersection of the cam disc circumference and theradius k pass the roller 19 the squeegees 34 (which have meanwhilearrived again in their extreme left hand or, as shown in Fig. 4, righthand position) also will have reached their lowest position and havecome to rest between the printing `colour 45 present on the closed edge50 of each screen and the associated screen frame 37.

`When the cam disc 46 continues rotating, the printing colour 45 ispushed off said closed screen edge 50 by each squeegee (then moving tothe left according to Fig. 4) during the time when the cam disc coversthe angle between the cam discovers the angle between the radii l and mthe squeegees will push the printing colour 45 onto the opposite closedscreen edge 50, and immediately tit) the radii k and l; during the timewhen yhave reached their highest position,

is lifted off the associated according thereafter each squeegee `34screen (the opposite stroke a of the squeegees to Fig. 4).

During the time when the cam disc 46 covers the angle between the radiin and o the squeegee carrier 14 together with the squeegees 34 is liftedhigher and also the screen support is moved upwardly.

After the screen support and the squeegee carrier 14 the advancement ofthe belt 26 with the fabric 28 to the next position starts.

During this advancement of the belt 26, which continues until the radiusI of the cam disc 46 passes the roller 19 again, the squeegees 34 intheir lifted position perform the inoperative strokes b and c which havealready started in the meantime (Fig. 4). During the subsequent completerevolution of the cam disc 46 the squeegees 34 continue moving withoutcoming to a stand still, for performing an operative stroke a and twoinoperative strokes b and c, this time, however, according to the mirrorimage of Fig. 4, while during the operative stroke the printing colour45 is pushed in opposite direction across the screen having the newportion of the fabric to be printed located thereunder. This continuesas long as the cam disc 46 rotates.

According to the embodiment the belt 26 is periodically advanced over adistance e (Fig. 5) so that each printed portion of fabric 28 isadvanced first to an intermediate position and subsequently to the nextprinting position.

Because during the operation of the screen printing machine the squeegeecarrier 14 with the squeegees 34 continues moving, high printing speedscan be reached, while the chance of misprinting is minimized.

Although according to the embodiment described each squeegee performstwo inoperative strokes in its lifted position, which strokes start justbefore the squeegeed mass of printing colour and which end just behindsaid mass, whereupon each squeegee performs one operative stroke, itwill be clear that a number of operative and a subsequent number ofinoperative strokes of the squeegee or squeegees may be selectedaccording to requirements, provided that the shape and the speed ofrevolution of the means for periodically driving the belt and forcontinuously driving the squeegee carrier, as well as the lifting andlowering of the squeegee carrier and the screen support be adaptedthereto.

If the number of operative strokes is larger than l, the cam disc mustbe provided with a corresponding number of cams to lift only thesqueegee carrier. The screens then remain in their places.

The only possibility of the operation getting out of .tune resides inthe one way coupling. If however, the

lengths of repeat are normalized to multiples of a given unit of length,this coupling can be replaced by a ratchet so that mistakes areexcluded.

The construction described admits of very high printing speeds with aminimum chance of misprinting, because the possibility of one of theoperations being skipped is excluded.

I claim:

l. A screen printing machine for sheets and lengths of textile, paperand the like, comprising a main frame. two rollers and two shaftsrotatably mounted on said frame, an endless belt supported for movementon said rollers and adapted to carry the material to be printed, one ofsaid rollers having a one-way driving pulley thereon, adjustable meansfor intermittently moving said belt mounted on the first of said twoshafts and comprising an arm having an adjustable sleeve thereon and aspring tension cable attached at one end to said sleeve and passingaround said one-way pulley and having the other end attached to saidframe, a screen support mounted above the endless belt, a squeegeecarrier mounted above the screen support and provided with a number ofsqueegees fixed to the carrier, means for continuously reciproeating thesqueegee carrier mounted on said second shaft and comprising an arm anda link pivotally connected to one end of said arm with the free end ofsaid link pivotally connected to said squeegee carrier, means forperiodically first lifting the squeegee carrier from the screen supportand subsequently the spaced squeegee carrier and screen support from theendless belt and for first lowering the spaced squeegee carrier andscreen support towards the endless belt and for subsequently loweringthe squeegee carrier towards the screen support, said means forintermittently moving the endless belt being operable during the liftingof the squeegee carrier and the screen support7 and means on said framefor driving the second shaft at least one and one-half times as fast assaid first shaft and for driving said lifting means.

2. A screen printing machine for sheets and lengths of textile, paperand the like, comprising a main frame, an endless belt supported formovement on the main frame and adapted to carry the material to beprinted, adjustable means for intermittently moving said belt, a screensupport mounted above the endless belt, a squeegee carrier mounted abovethe screen support and provided with a number of squeegees fixed to thecarrier, means for continuously reciprocating the squeegee carrier,means for periodically'iirst lifting the squeegee carrier from thescreen support and subsequently the spaced squeegee carner and screensupport from the endless belt and for first lowering the spaced squeegeecarrier and screen support towards the endless belt and for subsequentlylowering the squeegee carrier towards the screen support comprisng apair of levers pivoted at their centers to said frame in thelongitudinal direction thereof and having their adjacent ends pivotallyconnected to each other, a pair of rollers mounted at the ends of saidlevers opposite said pivotal connection on which Ysaid squeegee carrierrolls, a follower wheel suspended from one end of said levers, pinsadjustably mounted on said screen support over the ends of said leversopposite said pivotal connection and adjusted to contact the ends ofsaid levers after said levers have been pivoted from the horizontalposition, and cam means rotatably mounted on said frame contacting saidfollower wheel and adapted to urge said wheel upwardly to pivot saidlevers and thus lift said squeegee carrier and to continue to urge saidwheel upwardly to bear against said pins and lift said screen support intimed relation to said means for moving said belt, said means forintermittently moving the endless belt being operable during the liftingof the squeegee carrier and the screen support, and means on said framefor driving said belt moving means, said reciprocating means and saidlifting means.

3. A screen printing machine as claimed in claim 2 in which said cammeans has a prolile to lift the squeegee carrier from the screen supportat the end of at least one operative stroke of the squeegee carrier andto lower the squeegee carrier toward the screen support at the end of atleast two following inoperative strokes of the squeegee carrier.

References Cited in the lile of this patent UNITED STATES PATENTS2,612,835 Marek et al Oct. 7, 1952

